The interior surfaces of tin roof panels are particularly prone to collecting condensation. Unfortunately for homeowners, condensation can lead to serious damage, including roof leaks, damps spots, mould and mildew growth, blistering paint and even insect infestation. Fortunately, there are steps you can take to limit condensation on tin roofs.
Install attic vents. Attic ventilation will help prevent condensation on your tin roof. According to Dale Dorman, Extension Housing and Environment specialist with the University of Georgia, attics require one square foot of unobstructed ventilation area for each 150 square feet of attic area. Five vent types are commonly used in attics, including eave, gable, turbine and continuous ridge.
Increase circulation. Circulation helps prevent condensation. Boost circulation by setting up small, efficient fans throughout your house or by using air-to-air heat exchangers. An air-to-air heat exchanger has two fans, one that forces warm, moist air out of the home and another that brings cold dry air from outside.
Reduce moisture in the air in your home. Run a dehumidifier in the winter months and an air conditioner in the summer months. You can purchase a hygrometer at hardware stores that will tell you the relative humidity in your home. Ideally, the relative humidity should remain between 30 and 50 per cent.
Reduce moisture-generating activities. Limiting the domestic activities, such as laundering, bathing and cooking, that produce moisture can help prevent roof condensation.
Apply a vapour retarder to the underside of the roof. Two of the most effective vapour retarder materials are polythene plastic sheets and two-ply fibreglass felts adhered in hot asphalt. But any material that has a permeability rating of 1.0 or less may be an effective vapour retarder.